To the american



No. 608,8I9. Patented Aug. 9, I898.

w. R. WOOD.

UNDERFEED STOKEB.

(Application filed Apr. 29, 1897.)

4 Sheets-Sheet I-.

(No Model.)

U unanwwwww. uuuuuu I WITNESSES y Patented Aug. 9, I898. W. R. WOOD.

UNDERFEED STOKEB.

(Application filed Apr. 29, 1897 4 Sheets-Sheet 2.

(No Model.)

WITNESSES :Rs co. PHOTO-LIT No. 608,8l9. Patented Aug. 9, [898. W. R. WOOD.

UNDERFEED STOKER.

(Application filed Apx. 29, 1897.)

4 sheets-fshee't 3.

(No Model.)

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Warren Snares Arrest tries.

WILFRED R. VVOGD, OF DAYTON, OI'IIO, ASSIGNOR TO TIIIC AMERICAN STOKER COMPANY, OF SAME PLACE.

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SPECIFICATION forming part of Letters Patent No. 608,819, dated August 9, 1898. Application filed April 29, 1897. Serial No] 634,442. (No model.)

To all whom it may concern.-

Be it known that I, WILFRED R. Wool), a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Underfeed Stokers, of which the following is a full, clear, and exact description, reference being bad to the accompanying drawings, forming part of this specification.

My invention relates to improvements in that class of underfeed stokers in which coal or other fuel is fed continuously into a magazine which is surmounted at the top with twyers for the delivery of air or air and steam at or near the point of combustion, which takes place above the point of delivery of the fuel into the magazine.

The object of my invention is to increase the durability, simplicity of construction, and efficiency of action of this class of stokers, and its novelty will be hereinafter set forth, and specifically pointed out in the claims.

The followingis a description of the accompanying drawings, which show my invention embodied in the form at present preferred by me; but it will be understood that various modifications and changes may be made without departing from the spirit of my inven-' tion and without exceeding the scope of the claims. i

In the accompanying drawings, Figure 1 is a longitudinal sectional view, in side eleva-' tion, of a furnace equipped with my improved stoker. Fig. 2 is a plan view of the working parts of the stoker, some of the twyer-blocks being removed and a portion over the motor being broken away. Fig. ,3, Sheet 2, is aside elevation of the forward part of the same, partly broken to show the arrangement of the air-controlling devices. Fig. 4, Sheet 2, is an enlarged detail in transverse section, showing the manner of securing the twyerblocks to the retort or magazine. Fig. 5, Sheet 2, is a broken side elevation looking toward the left of Fig. 1. Fig. 0, Sheet 2, is a sectional detail representing a modification in the construction of Fig. at. Fig. 7, Sheet 3, is a transverse section through the feeding- Fig.

same. Fig. 14:, Sheet 1, is a plan View of the same. Fig. 15,' Sheet 1, is a sectional side elevation of the ballbearing mechanism. Fig. 16, Sheet 4, is an elevation of one-half of the ball-bearing mechanism. Fig. 17 is an enlarged elevation of the actuating-dog.

The same letters of reference are used to indicate identical parts in all the figures.

Referring to Figs. 1 and 2, A is the combustion-chamber of a boiler or other furnace, of which B is the front wall. Set in this furnace with its top about level with the grate surface or floor of the fire-chamber is an oblong trough-shaped magazine or retort O with sloping sides and an upwardly-sloping rear end, and extending forward from the retort through the front wall of the furnace is a tubular conduit D, whose bottom is flush with the bottom of the retort, as seen in Fig. 1, and whose forward end communicates with the lower end ofithe fuel-hopper E. Journaled axially through the conduit D is a screw conveyer F, which enters the retort C and terminates at a point about two-thirds of the length of said retort, as seen in Fig. 1. This screw conveyer is composed of a poly; onal shaft, on which are strung the sections of interlocking flights a, whose hub portions 5 have bores through them to snugly fit the shaft and conforming to its shape in transverse seetion. Theflights and hub portions within the conduit are of uniform diameter, and the edges of the former closely fit the inner walls of the conduit. From the mouth of the conduit, where it enters the retort C, the hub portions are gradually tapered and enlarged from the front to the rear, as seen in Figs. 1 and 2, so as to gradually reduce the carrying capacity of the flights as they extend toward the rear of the retort; also, if

desired, the flights themselves may be grant ually diminished in diameter as they extend toward the rear of the retort to aid in reducing their carrying capacity.

I will now describe the manner of supportin g and j ournaling the screw conveyer, reference being had particularly to Figs. 1, 9, 13, 15, and 16. Suitably secured upon the front of the conduit D is aplate or bearing-piece c, Fig. 13, in which is a vertical socket to receive a pair of washers or bearing-rings (Z, Figs. 15 and 16, having their adjacent faces annularly grooved to receive and retain bearing-balls 6, preferably of chilled steel, and fitted upon the shaft f of the screw conveyer, so as to turn therewith, is a'shouldered sleeve g, the enlarged part of which is j ournaled in and has its bearin g in the rear wall of the plate 0 and the smaller part of which extends through the bores of the ring dand is j ournaled in the front wall of the plate c. It will thus be seen that the shoulder of the collar 9 bears against the inner ring and the entire end thrust of the screw conveyor is borne by the balls, the construction forming a very perfect ball-bearin g to receive the end thrust. In the Wall of the the conduit, is asemicircular recess in which is removably secured, by means of bolts h, a bearing-plate 1', whose inner side conforms to the curvature of the conduit and against which the flights of the convcyer hear at that particular point, thus serving to hold the conveyer down to its work and to a large extent relieving the bearings in the plate a.

To actuate the screw eonveyer to feed the coal from the hopper E through the conduit D into the retort or magazine 0, I employ the following mechanism, particular reference being had to Figs. 12, 13, 14, and 17: Fast on the shaft f in front of the bearing-plate c is a ratchet-Wheelj with its hub extended on both sides, on which hub is journaled a twopart sleeve 76, each of which parts has secured to it an upwardly-extending arm Z and a dowmvardly-extendin g arm m. Between the arms m is pivoted a double dog 01 (see Fi 17) with two engaging noses 0 j.) and with two pivotal bearings q 0, preferably connected by a slot 8, so that the dog may be instantly shifted from the pin carried by the arms m to cause either the bearing q or the bearing r to engage the ratchetj. For instance, the dog-carrier composed of the parts 7s at has a constantly vibrating or reciprocating motion imparted to it by any suitable 1neans--in this instance by a well-known form of steam-motor Gr, whose piston is connected by pivoted links t to the u pwardly extendin g arms Z-and when the nose 0 engages the ratchet, with the bearing (1 on the pin of the arms m, as in Fig. 12, the ratchet, together with the screw conveyer, will be turned in such direction as to feed the coal into the retort; but when the dog is shifted to cause the nose to engage the ratchet, with the bearing 1' on the pin, the

the retort entirely.

i 011 Sheets 1, 2, and 3. zine O and some little distance from it is a jacket or easing H to form a wind-box, en- 1 tering which and under the conduit D is an vibration of the dog-carrier will cause an opposite direction of rotation of the ratchet and screw conveyer, which would feed the coal from the retort back into the hopper. This backward rotation of the screw conveyer is sometimes important both to relieve temporary clogging andwhen it is desired to empty To insure the proper working of the ratchet-wheel and screw conveyer, so that they may turn continuously and intermittingly in one direction, I employ a stop-dog a, Fig. 12, preferably in two parts of unequal lengths and pivoted by a removable pin in a lugr, vertically adjustable on the inner wall of the case surrounding the ratchet. As seen in Fi 12, there are two of these lugs 0 one on each side of the ratchet, and when the nose 0 is in engagement with the ratchet the two-part dog a is on the left; but when the dog a is shifted to bring its nose 19 into engagement the two-part dog a is likewise shifted to engage the lug 'u on the right. By these means very nice and perfect adjustments can be made'to insure the constant intermitting rotation of the screw conveyer, as will be i readily understood.

conduit 1), Figs. 1 and 9, at the rear end of 1 I will now describe the air-blast mechanism for supplying the requisite amount of oxygen 3 to the fuel at or about its zone of combustion,

particular reference being had to the figures Surrounding the magaair-trunk I, connected to any suitable blast apparatus, the force of the blast being regulated by a gate or valve J, Figs. 1 and 3, pivioted, as at a, and controlled by a lover a Lwith an operating-handle d having a rack engaging a fixed latch-piece a, in this instance on the side of the casing surrounding 1 the ratchet-wheel j. 5 form part of the conduit from the blower to E the twyer-openin gs. The top of the magazine O and the top of the jacket 11 are connected by a horizontal flange 1), which, as seen in ,Fig. 4, may be an extension of the magazine C, or, as seen in Fig. 6, may be an ex- 5 tension of the jacket ll, suitable bolts b be 1 ing provided to unite them at their point of I juncture.

The trunk I and box ll The horizontal flange b isperforated with openings U, (see particularly Figs.

f2 and 5,) and there is seated on the flange twyer-blocks c, which extend upwardly from the flange, so that their inner faces form a substantial continuation of the sides of the retort, though preferably at a slightly-different angle, as shown in Fig. 4. are hollow, their lower openings registering 3 with the openings b in the flange Z), and are @provided 011 their inner faces with suitable outlet-openings c and on their outer faces along the sides of the magazine and just above These twyer-blocks the grate level or floor of the fire-chamber with other outlet-openings 0 (See Fig. 4-.) These blocks are arranged entirely around the top of the magazine, with their ends abutting to form a continuous wall or wall extension around the top of the magazine. Each of the twyer-blocks is provided with a downwardlyprojeeting flange 0 adapted to fit into one of the openings the sides of the flange and the opening being preferably correspondingly tapered, so as to form a close joint to hold the twyer-blocks snugly in position. To secure the twyer-bloeks upon the flange and also to permit of their ready removal for repair, replacement, or otherwise, I provide in both ends of each lawyer-block, near its bottom, a recessed opening clhaving acountersunk portion o to receive one end of a T-headed bolt 0 which projects downwardly at an angle through the flange b and through suitable lugs cl and is held by a nut on its threaded end. The countersunk portion 0 of the recessed opening 0 is provided with a depressed seat 0 ada ted to receive the re 'ectin ends of the head of the bolt 0 when the same is turned in line with the sides of the magazine. The construction is such that by loosening the nuts 011 the bolts and turning them on their axes until the T-heads stand at right angles to the sides of the magazine the twyer-blocks may be raised and removed from the flange or may be replaced thereon, as desired, and by having the bolts extend at an angle through the sides of the air-jacket beneath the gratesurface they may be readily gotten at.

In order to distribute or deflect the air to one side or the other of the magazine, I place in the trunk I a deflector K, which stands vertical in the trunk and is pivbted therein, so as to be moved at different angles, and as a convenient means of operating said deflector its pivot projecting through the trunk is provided with an arm connected by a pivoted link k to an operating-lever 71: pivoted to the side of the trunk, as shown in Fig. 3.

Secured within the Wind-box, preferably to the under side of the magazine, is another stationary deflector L, Fig. 1, to aid' in the proper distribution of the air to-the twyers.

The fuel-conduit D is provided on its upper side, adjacent to the magazine, with a pocket 6, having curved or inclined sides, (see Figs. 1, 2, 7, 8, 9, 10, and 11,) and to this pocket air is supplied by means of a suitable pipe 6 which As the retort or magazine 0 may be sub jected to strains liable to crack or break it, either from expansion, contraction, or otherwise, I provide it with one or more transverse sets of adjacent lugs m and between which the metal of the bottom and sides of the mega zinc is made thinner than the rest of the body of the magazine. In this instance I have shown two sets of such lugs, which have bolts passed through them, though not tightened up, forming bridges across the lines of diminished resistance, and should anybreaking strain occur to the retort it would break' or crack between said lugs, and the bolts could then be tightened up to hold the parts securely together without necessitating the removal of the retort and its replacement by a new one, as will be readily understood.

As seen in Fig. 13, all that part of the motor mechanism in front of the hopper E is inclosed by a suitable casing N, preferably constructed with removable sections to give ac cess to the parts, and fitted upon the front end of the shaft 7a is a cap m Visible through a circular opening in the front of the case N and carrying some distance from its center a piece n projecting through the opening in the case, which piece is preferably a grease cup communicating with the bearings within the case, and thus serving the double purpose of a lubricator and an indicator to enable the attendant at all times to see at a glance that the screw conveyer is properly rotated and also in which direction it is rotated.

It will be seen from the above description that I provide a stoker in which the parts are simple and compact with a self-contained motor driving mechanism. The constructions are such that all parts liable to require repairs are easily and readily accessible. By having the air-chamber completely surrounding the magazine and communicating directly with an air-trunk, which partially surrounds the conveyer, the incoming air pre vents the overheating of the conduit or magazine, and at the same time the cooling of the magazine and conduit tends to slightly heat the air which is introduced through the twy ers, thus producing a desirable effect both from the standpoint of economy of combustion as well as economy of construction.

Having thus fully described my invention, I claim- 1. In an underfeed stoker, the combination of a retort ormagazine, aseries of twyer-openings on both sides, said openings being directed across the magazine, a second series of twyer-openings above the floor of the firechamber directed away from the magazine, and means for forcing air through said twyeropenings, substantially as described.

2. In an underfeed stoker, the combination of a retort or magazine, a series of openings in the upper part of saidmagazine discharging toward the interior thereof and additional openings above the floor of the fire-chamber directed away from said magazine, and means for forcing air through said openings, sub stantially as described.

8. In an underfeed stoker,the combination of a retort or magazine provided with a series of twyer-openings at or near its top, a windconduit communicating with the twyer-open ings, and a deflector in said wind-conduit, subchamber with openings in said flange having stantially as described.

4. In an underfeed stoker, the combination of a retort or magazine provided with a series of twyer-openings at or near its top, a

wind-conduit communicating with the twyeropenings, and an adjustable deflector in said sion for the top of said magazine,substantially wind-conduit, substantially as described.

5. In an underfeed stoker, the combination of a retort or magazine provided with a series of twyer-openings at or near its top, a j

jacket entirely surrounding said magazine to form a wind-box and communicating with the twyer-openings, a wind-trunk communicating with said wind-box, and a deflector, substantially as described.

6. In an underfeed stoker, the combination of a retort or magazine, a jacket surrounding the same to form a wind-box, provided with openings, and a series of twyer-blocks seated thereon and provided with openings communicating with the openings in the wind-box,

substantially as described.

the same, twyer-blocks arranged at the top I of said magazine and communicating with Said conduit, and an air-trunk partly surrounding said conduit and communicating with said magazine, substantially as described.

9. In an underfeed stoker, the combination 5 k feed stoker, the combination of a screw conveyer, a ratchet for operating the same, a viof a magazine, a jacket to form an air-chamber around said magazine, twyer-blocks communicating with said air-chamber and bolts adapted to engage in recessed openings in the abutting ends of said twyer-blocks, substantially as described.

10. In an underfeed stoker, the combination of a magazine, a laterally projecting flange therefrom, an air-chamber surroundi-ng said magazine, twyer-blocks mounted f thereon, and bolts extending through said 2' flange and having heads adapted to engage oppositely-arranged recessed openings in adjacent ends of said twyer-blocks, substantially as described.

11. In an underfeed stoker, the combination of an air-chamber a fuel-magazine, an air-trunk, and a fuel-conduit, said air-chamber surrounding said magazine and said airtrunk partly surrounding said conduit, of a pocket in said conduit and an air-pipe leading from said air-trunk to said pocket, substantially as described.

' 12. In an under-feed stoker, the combination of a fuel-magazine having an air-chamber completely surrounding the same, a lat- 1 erally projecting flange connecting the tops of both and adapted to form a top for said air- Q tapered sides, and twyer-blocks having correspondingly-tapered flanges to fit in said jopenings, said twyer-blocks being formed with openings on the faces thereof, and adapted to fit together to form a continuous extenas described.

13. In an underfeed stoker, the ball-bearing mechanism for the screw conveyor con- 5 sisting of the recessed plate a, annularly- 3 grooved rings d in said-recess, balls 6 in said 1 grooves between the rings,and the shouldered sleeve g fast on the conveyer-shaft and having insaid plate 0 substantially as described.

14:. In the motor mechanism of an underfeed stoker, the combination of a screw conveyer, a ratchet for operating the same, a vi- 1; brating dog-carrier with means for vibrating 1 the same, and a double-nosed dog having two pivotal bearings connected by a slot pivoted i to said carrier and adapted to be shifted so that either nose may engage the ratchet to control the direction of revolution of the screw conveyer, substantially as described.

15. In the motor mechanism of an underfeed stoker, the combination of a screw conveyer, a ratchet for operating the same, a vi brating dog-carrier with means for vibrating the same, a double-nosed dog having two pivotal bearings connected by a slot pivoted to said carrier and adapted to be shifted so i that either nose may engage the ratchet to .fcontrol the direction of revolution of the screw conveyer, and a stop-dog for said ratchet f adapted to be shifted to either side thereof 5 substantially as described.

16. In the motor mechanism of an underbrating dog-carrier with means for vibrating the same, a double-nosed dog pivoted to said carrier and adapted to be shifted so that either nose may engage the ratchet to control the 1 direction of revolution of the screw conveyer,

; and a twopart stop-dog, of unequal lengths,

for said ratchet adapted to be shifted to either side thereof, substantially as described.

17. In the motor mechanism of an underfeed stoker, the combination of a screw conveyer, mechanism for actuating the same, a Y casing for said mechanism provided with an opening in front, and an eccentrically-set i11- 18. In the motor mechanism of an underfeed stoker, the combination of the screw-conveyer ratchet and its vibrating dog-carrier 7a of the double-nosed dog 02 having two pivotal bearings q 0" connected by a slot 8, subl stantially as described.

19. In an underfeed stoker, the combination of a fuel-magazine, a fuel-conduit leading therefrom, a fuel-hopper for said conduit, ness than the body thereof combined with a and a screw conveyor in said conduit and bridge or biidgesspanning the same, whereby :0 magazine and joui'naled through the front the parts are held together in case of fracture. Wall of said conduit and having a removable a bearing-plate Within the conduit at its rear WILFRED end, substantially as described. Witnesses:

20. In an underfeed SlJOkQl a fucl-inaga- HARRY O. TRIPP, zinc having one or more portions of less thiek- GILBERT H. WILLIAMS. 

